Endocrine II: Thyroid, Parathyroid, and Pancreas Flashcards
What provides blood supply to the thyroid?
Superior and inferior laryngeal arteries
True or false: You cannot live without either your thyroid or parathyroid hormones
False- you can live without thyroid hormones, but not parathyroid hormones
What is the functional structure of the thyroid?
Thyroid follicles
What are the pink globs seen in thyroid tissue?
Colloid- T3 and T4 stored as thyroglobulin
What cells act as the gatekeepers of colloid storage?
Follicular (Principal) cells
What are the two cell types within the thyroid?
Principal cells and parafollicular cells
What cells make up the follicular epithelium and line follicles?
Follicular (Principal) cells
What type of capillaries surround a thyroid follicle?
Fenestrated
What is the function of thyroid follicular cells?
Synthesis, storage, and release of thyroid hormones
Where are parafollicular cells found within the thyroid? What do they look like?
Large, lightly staining cells between the plasma membrane and basal lamina of the follicular cells
What is the principal hormone release by parafollicular cells?
Calcitonin
What creates the little white “scalloped” appearance within thyroid follicles? What is the appearance of follicular cells surrounding the scalloped colloid?
Occurs when the follicle is actively taking up colloid; large/swollen
Which thyroid hormone is more prevalent in the bloodstream? What thyroid hormone is more active?
T4 is more prevalent and T3 is more active
What cell types can be found within the parathyroid? What is the predominant cell type?
Principal “chief” cells and oxyphil cells; chief cells predominate
Which cells of the parathyroid contain secretory granules? Which cells are larger?
Chief cells; oxyphil
What is the function of chief cells?
Synthesis of parathyroid hormone that increases serum calcium
True or False: Parathyroids are not under neuroendocrine regulation
True
What kind of gland is the pancreas?
Both endocrine and exocrine
How do the islets of Langerhans appear relative to the surrounding pancreas tissue?
Eosinophilic
What is the name of the exocrine cells of the pancreas?
Pancreatic acinar cells
What is the most numerous cell within the islets of langerhans?
Beta cells
Where within the islets of Langerhan are beta cells typically located?
In the middle
How do the granules of alpha, beta, and delta cells appear?
Alpha granules are fairly solid with a dark core and lighter halo; beta granules have crystalloid inclusions surrounded by translucent zone; delta cells light and uniform
What are the primary products of the cells within the islets of Langerhans?
Alpha- Glucagon; Beta- Insulin; Delta- Somatostatin
